Parallel builds

Remember that builds happen in parallel by default. This is more apparent now as we add multiple sources to our build. Packer’s strength becomes more apparent in a multi-cloud deployment. Remember that Packer is a tool, not a platform or a service. Packer can be run whenever or however you want it to, but it must also be used responsibly. If you accidentally kick off 50 builds in parallel, they will all be started simultaneously. There is also no locking or state file, as with Terraform, so you may accidentally run the same build multiple times simultaneously, which will probably not be what you intended. If you use unique identifiers for each build instance, they will all build simultaneously. If you use fixed naming, then likely Packer’s builders will error, saying that certain resources it needs to create already exist and can’t be replaced.

In the early days of Packer’s in 2017, HashiCorp built a managed platform called Atlas, which...